Electro-magnetic pump with vibratory movement for gaseous fluids



Nov. 14, 1933. G. NAHMAN ET AL 1,934,994

ELECTROMAGNETIC PUMP WITH VIBRATORY'MOVEMENT FOR GASEOUS FLUIDS Filed June 18, 1932 M r/0A INVENTORS:

Gustave Nahman.

Raincro Stratta. Ettore Vernazza.

Patented Nov. 14, 1933 UNITED STATES ELECTED-MAGNETIC PUMP WITH VIBRA TOBY MOVEMENT FOR GASEOUS FLUIDS Gustave Nahman,

Alexandria,

Egypt, and

Rainero Stratta and Ettore Vernazza, Turin,

Italy Application June 18, 1932, SerialNo. 618,058, and in Italy June 24, 1931 10 Claims.

Several electro-magnetic pumps are known wherein the pumping parts moves alternately under the impulse of at least one electro-magnet fed by a variable current, and of energy recuperating means such as springs. In most of these apparatus, the variations of the magnetic field are produced by a special mechanism; in others, the feeding is done directly by an industrial alternating current with a frequency exceeding generally 20 cycles per sec. every cycle producing 4 single strokes of the armature. At such a frequency, the amplitude of oscillation of the armature cannot, on account of the inertia effects, exceed some tenths of a millimetre. Despite the 15 unquestionable advantages resulting from the j simplicity of their construction and from their direct adaptability to the most used currents, the pumps of this kind have met with little success in the handling of liquids, and none in that gaseous fluids. The object of the present invention is an electro-magnetic pump which is specially intended for gaseous fluids; it works at high speed and has a very small amplitude of vibration. Said result is obtained by combination of several improvements such as increase of the useful efiect through reduction of the dead space in the pump body, assured synchronism between the oscillations of the magnetic field and the oscillatory o movement of the armature by its rebounding in normal work at the ends of its strokes, the noiseless construction of the machine and the reduction of its volume.

The annexed drawing shows a form of construc- 35 tion of the pump for working with industrial alternating current. Figure 1 is a section on a vertical and axial plane of the machine. Fig. 2 is a half section on a vertical axial plane perpendicular to the section of Fig. 1. Fig. 3 shows the pump in two horizontal half sections on the line 3a:--3:c of Fig. 1. Fig. 4 shows in plan a form of construction of the piston. A

The motive apparatus of the pump comprises two laminated electromagnets 1 and 2 in the 5 shape of a 0, each provided with two coils 3. These electro-magnets, placed with their like named poles on the same side, are fixed flat by screws 4 on a bridge 5 and under the mobile laminated armature '7. The pump consists of a pump body 50 8 shaped as a hollow disc and provided with a suction valve 9, a delivery valve 10 and a piston made of rigid discs 12, 13 hollowed at 14, and clasping between them a diaphragm 15. Perfect tightness of the piston is obtained by means 55 of the outer part of the diaphragm which part ,tm 1 and 2, act in the opposite direction to the mag- 7 is very flexible as compared with the middle part and is clasped by screws 16 between the rim of disc 8 and a ring 17 which is part of the bridge 5.

In this form of execution, the pumping is done by the piston, as the free annular part of the 0 diaphragm has a limited surface. The hollows 14 are of use for lightening the piston and diminish its sonorousness. This piston is fastened to the armature 7 by means of a guiding stem 18 which serves at the same time as a bolt and whose ends 5 are guided and slide in bearings 19 and 20 being respectively parts of the pump body 8 and the bridge 5. Two helical springs 21 and 22', lodged the space surrounded by the electro-magnet netic attraction. Said springs bear on two set screws 23 engaged in two arms 24 of the bridge 5, making a cross with it. A large flange of the stem 18 serves to produce axial rebounding of the mobile element against the pump body at the limit of the stroke caused by the action of the springs 21, 22. The dimensions of the dead space are reduced to the utmost, and are just suflicient to prevent the piston from striking the pump body in the part surrounding the flange. For the same purpose, the inner surface of the pump body adapts itself exactly to the inner surface of the pumping part. The whole of the pump is suspended elastically within a noise deadening box 26 by means of two pairs of helical springs 27, 28 acting by compression and placed in two vertical and perpendicular planes passing through the axis of the machine. The whole of the pump is maintained centered in the noise deadening box by a hood 29 of elastic material; said hood is clasped at its periphery by a ring 30 on a rim 31 of the pump body 8, and at its centre, between the lid 32 of the box and a tubular union 33 for the outlet of the compressed fluid. In the bottom of the box 26 are two holes 34 through which the screws 23 can be set. The box forms a suction chamber for damping the sonorous pulsations of the fluid which enters through the holes 34. The machine is placed preferably upon a base of felt which has the double advantage of reducing the vibrations and filtering the fiuid before it enters through the holes 34.

The pump works as follows: when the alternating current is sent through the windings of the electro-magnets, the latter attract the armature '7, compressing the recuperating springs 21,

22. The armature is pushed back by the same springs when the magnetic flux tends to zero. The piston, thus submitted to an alternate motion, sucks the fluid through the holes 34 and the valve 9, and forces it through the valve 10 into a compression chamber limited by the rim 31 and the elastic hood 29, from which chamber the fluid passes through the tubular union 33. Despite the high frequency of the strokes of the piston, the number of which, in the apparatus described, may exceed 250 per second, and despite the very small amplitude of said strokes and the relatively great and variable forces acting on the mobile element, the vibrations of said element are maintained exactly in synchronism with the oscillations of the magnetic field. This synchronism, which is indispensable for the good working of the apparatus, is obtained chiefly by means of the rebounding of the mobile element against a fixed hard and elastic surface. The rebounding accelerates the speed of each stroke, and thus secures regular working at high speed. The rebounding on a surface not fixed, acting as a spring would produce an inverse eifect. The acceleration of speed permits longer strokes, which increase materially the efilciency of the pump. Owing to the said rebounding, heavier mobile elements may be used, that is to say, more powerful apparatus, since the dynamic energy is carried over, without sensible loss, from one stroke to the other. The increase of speed and amplitude of the strokes produces on the fluid more energetic pulsations with better control of the valves. The rigid coupling of the piston with the armature assures, for the mobile rigid element so formed, a rectilinear working oscillation free of all parasitic and harmful vibrations. The use of a piston instead of a diaphragm gives to the pump, for a given stroke, a much larger output, which constitutes in this special case an appreciable advantage, considering the obligatory smallness of the stroke. Moreover the piston is, much less than diaphragms, subject to parasitic vibrations, these latter being caused principally by the flexing of these parts. The flat disposition of the c-shaped electro-magnets is of great advantage for the reduction of volume of the apparatus; it reduces its height and makes the suspension of the pump easier. Besides, this arrangement permits the use of broad shallow and very light armatures giving a better output for the pump. For pumps provided with armatures of the same section, that is to say, of equal power, the weight of the armatures is proportional to their length, the length being equal to twice the height of the armature plus the distance between the ends of the electro-magnet, from which it is deduced that the weight is essentially proportional to the height of the armature.

In the example of construction hereinbefore described the movable element rebounds on the one hand against the pump body and on the other hand against the polar faces of the electronets. In order to avoid wearing. out of said polar faces and to obtain a better rebounding, a second rebounding surface may be placed centrally at the side of the polar surfaces.

The above described form of construction may, within the scope of the invention, be modified in various ways; for instance, it is possible to design a pump provided with a number of pumping bodies fitted on the same shaft, said pumping members operating with single or double action; furthermore, it is obvious that the armature may be provided also with windings.

We claim:

1. In electromagnetic pumps comprising at least one electro-magnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding the pumping body to form a pressure chamber and supporting the electro-magnets, at least one fixed means for the rebounding under normal operating conditions, of the movable part when the air gap is at the maximum, and a casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped.

2. In electromagnetic pumps comprising at least one electro-magnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding .the pumping body to form a pressure chamber with an extremely reduced dead space and supporting the electro-magnets, at least one fixed means for the rebounding, under normal operating conditions, of the movable part when the air gap is at the maximum, and a casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped.

3. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part and working as a piston internally of a fixed body, with an extremely reduced dead space, a very flexible annular membrane clamped to the periphery of the pumping body and respectively to the interior of the fixed body to secure an air tight connection between the same, at least one fixed means for the rebounding, under normal operating conditions, of the movable part when the air gap is at the maximum, anda casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped.

4. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding the pumping body to form a pressure chamber with an extremely reduced dead space, and supporting the electro-magnets, a casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped and a flexible partition within said casing to separate the compression side from the suction side.

5. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding the pumping body to form a pressure chamber and supporting the electromagnets, a casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped, a flexible partition within said casing to separate the compression side from the suction side, and elastic means in said casing bearing against the fixed body of the pump to yieldingly suspend said body in said casing.

6. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a. vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding the pumping body to form a pressure chamber and supporting the electro-magnets, a casing containing said members and provided with inlet and outlet apertures for the fiuid to be pumped, a fiexible partition within said casing to separate the compression side from the suction side, and elastic means consisting chiefly of two opposite spring sets bearing against the fixed body and the casing, each set having a resultant passing through the centre line of the pump, to yieldingly suspend the fixed body of the pump in said casing.

7. In electromagnetic pump comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding the pumping body to form a pressure chamber and supporting the electro-magnets, a casing containing said members and provided with inlet and outlet apertures for the fiuid to be pumped, elastic means in said casing bearing against the fixed body to yieldingly suspend said body, and a flexible partition within said casing to separate the compression side from the suction side and to keep the fixed body of the pump centred in the casing.

8. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, a fixed body surrounding the pumping body to form a pressure chamber with an extremely reduced dead space and supporting the electro-magnets, two fixed central means disposed at both stroke ends of the movable part and used for the rebounding, under normal operating conditions-of said part at both stroke ends, and a casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped.

9. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable part, and a fixed body surrounding the pumping body to form a pressure chamber with an extremely reduced dead space, two C-shaped electromagnets supported by the fixed body through suitable means in the fiat position, with their like poles opposite one another, around the centre line of the pump, and a casing containing said members and provided with inlet and outlet apertures for the fluid to be pumped.

10. In electromagnetic pumps comprising at least one electromagnetic element consisting of a fixed part and of a movable part having a vibratory rectilinear motion, the combination of a pumping body fast to and actuated by the movable. part, a fixed body surrounding the pumping body to form a pressure chamber with an extremely reduced dead space, a bridge-piece fast to the fixed body to support two C-shaped electromagnets in the flat position, with their like poles opposite one another, around the centre line of the pump, and a casing containing said members and provided with inletand outlet apertures for the fluid to be pumped.

GUSTAVE NAHMAN. RAINERO STRATTA. ETTORE VERNAZZA. 

